I DONT UNDERSTAND MY HOMEWORK! please please please help me with these questions about reactions

please help me with these two problems? i dont understand them D;

In the reaction AgNO3(aq) + NaCl(aq) ---> NaNO3(aq) + AgCl(s), the reactants...
a.) gain electrons only
b.) lose electrons only
c.) both gain and lose electrons
d.) neither gain nor lose electrons

In the reaction Mg + Cl2 ---> MgCl2, the correct half-reaction for the oxidation that occurs is...
a.) Mg + 2e- ---> Mg(2+)
b.) Cl2 + 2e- ---> 2Cl-
c.) Mg ---> Mg(2+) + 2e-
d.) Cl2 ---> 2Cl- + 2e-

thank you :) 10 points best answer!!

In the first question the aqueous substances silver nitrate and sodium chloride already exist as separate ions (Ag+ , NO3- , Na+ and Cl-. After the reaction the separate ions join to form the solid AgCl leaving Na+ and NO3- still in solution. So the answer is "d" - they neither gain nor loose electrons, they just swap partners.

In the second question about oxidation, we must first understand what oxidation is. Oxidation is the process in which one atom or ion gives up one or more electrons to another atom or ion. In the beginning, Cl2 and Mg are both atoms, they are neutral. After the reaction both become ions. The Mg looses electrons to the chlorine atoms. Magnesium's oxidation number goes from 0 (as an atom) to +2 as an ion - its oxidation number goes up, so it is oxidized. he answer is "c" - Mg^0 ---> Mg^+2 + 2e-


ADDITION+++++++++++

In the next example, the reaction is certainly not spontaneous! Lots of energy must be put in to get it to occur. Its like the electrolysis of water - forcing the decomposition of H20 back into its elements H2 and O2. Nonetheless, KCl can be decomposed. When it happens, the chloride ion (Cl-) releases the extra electron it gained returning it to the potassium ion. Potassium is reduced since its oxidation number goes down from +1 to 0 and chlorine is oxidized since its oxidation number goes up from -1 to 0. The answer is "2" - potassium is reduced by gaining electrons

for number 1, it is d i believe because if you look at the oxidation numbers for both the cations, NO3 and Cl, they are the same. therefore there is no oxidation or reduction.

for number 2, it is c because the oxidation number of Cl is -1, therefore the Mg needs to have an oxidation number of +2. This means that it is undergoing oxidation, or loss of electrons, which in turn means it is c

1. d

2. c

bluh bluh oxidation numbers, you probably don't really care